Evaporative cooling of a heat exchanger in a compressor system

ABSTRACT

The present disclosure is directed to an air cooled heat exchanger with an evaporative cooling pad positioned upstream thereof to humidify and cool ambient air flowing into the heat exchanger. A water manifold is positioned proximate a top side of the evaporative cooling pad and a water tank is positioned proximate a bottom side of the evaporative cooling pad. The water manifold is operable for supplying water to the evaporative cooling pad at the top side and the water tank is operable for receiving water discharged from the evaporative cooling pad at the bottom side thereof.

TECHNICAL FIELD

The present application generally relates to heat exchangers and more particularly, but not exclusively, to evaporative cooling of heat exchangers in a compressor system.

BACKGROUND

Heat exchangers are designed to exchange heat between at least two mediums. Heat transfer capability in air cooled heat exchangers are limited by the ambient temperature of the air. Cooling the ambient air will increase the efficiency of the heat exchanger system. Some existing systems have various shortcomings relative to certain applications. Accordingly, there remains a need for further contributions in this area of technology.

SUMMARY

One embodiment of the present disclosure is a heat exchanger with an evaporative cooling pad disposed upstream thereto. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for heat exchangers with a unique evaporative cooling system. Further embodiments, forms, features, aspects, benefits, and advantages of the present application shall become apparent from the description and figures provided herewith.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of an exemplary compressor and heat exchanger system with an integral water tank according to one embodiment of the present disclosure;

FIG. 2 is an exploded perspective view of the system of FIG. 1 with a separate water holding tank;

FIG. 3 is an exploded perspective view of a portion of the heat exchanger system of FIG. 2; and

FIGS. 4A-4F are schematic illustrations of various heat exchanger configurations according to certain exemplary embodiments of the present disclosure.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the invention as described herein are contemplated as would normally occur to one skilled in the art to which the invention relates.

Heat exchangers can be used to control the temperature of fluids at various stages within a compressor system. The heat exchanger system described herein is operable to control temperatures of certain fluids in industrial compressor systems that are configured to provide compressed fluids at a desired temperature, pressure and mass flow rate. The term “fluid” as used herein, should be understood to include any gas or liquid medium that may be used in a heat exchanger system such as air, oil and/or coolants as defined in the present disclosure. When the term “heated air” or “gas” is used it should be understood that any working fluid can be substituted and not depart from the teachings of the present disclosure. When the term “water” is used, it should be understood that the term includes any liquid or mixture of liquids such as antifreeze solutions or the like, that may be absorbed by ambient air and then evaporated from the air in a heat exchanger.

Referring now to FIG. 1, a perspective view of an exemplary compressor system 10 is illustrated in a perspective view. The compressor system 10 includes a base 20 for supporting a compressor (not shown in this view) to rest upon. The compressor system 10 includes a cooling system 30 extending from the base 20 configured to provide cooling heat transfer to certain fluids egressing from the compressor such as compressed air and/or a lubricant in some embodiments. In general, a flow of ambient air illustrated by arrows 12 is drawn in to the cooling system 30 to cool fluid in one or more heat exchangers 14 and is subsequently discharged as relatively hot air as illustrated by arrows 16. It will be understood that the terms “cool” and “hot” are relative, and should not be read to mean absolute temperature values. In the disclosed form, an integral water tank 51 may be associated with the cooling system 30. A pump 52 is configured to receive recycled water thorough an outlet conduit 54 and transfer the recycled water to the cooling system 30 through an inlet conduit 56. The cooling system 30 will be described in more detail below.

Referring now to FIG. 2 and FIG. 3, an exploded perspective view of a portion of compressor system 10 is illustrated in FIG. 2 and an enlarged view of the cooling system 30 is illustrated in FIG. 3. The cooling system 30 includes an evaporative cooling pad 40 operable to provide evaporative cooling to ambient air represented by arrows 12. The evaporative cooling pad 40 operates to cool the ambient air by way of evaporation cooling in a manner known to those skilled in the art of heat transfer means. In general, a liquid such as water is provided to saturate the evaporative cooling pad 40 and as the ambient air 12 flows therethrough, the ambient air 12 absorbs some of the moisture. The evaporative cooling pad 40 can be made from any material effective in absorbing water. In one example, the material can be formed from one or more corrugated cellulose paper sheets.

In some forms the ambient air will carry water completely evaporated from the evaporative cooling pad 40. The ambient air is cooled through the evaporative effect of the evaporative cooling pad 40. The cooled ambient air will increase the effectivness in cooling downstream heat exchangers. In other forms some additional non-evaporated water mist may be carried or entrained by the ambient air. The additional water can be transferred to the ambient air by way of the water soaked evaporative cooling pad 40 and/or by an additional water spray downstream of the evaporative cooling pad 40. When the humidified moist ambient air 12 flows through the relatively hotter heat exchanger 14, any additional non-evaporated water will absorb heat from the heat exchanger 14 and evaporate. This additional water evaporation can provide additional cooling capability over that of the cooled ambient air.

The evaporative cooling of the ambient air 12 increases the efficiency of the heat exchanger 14. In some forms, the water may be cooler than the ambient air and thus the water may directly cool the ambient air. For example, the water source may pass through an additional cooler, such as geothermal heat exchanger or the like. Other forms of cooling the water, such as by way of example and not limitation a refrigerant cycle are also contemplated herein

The cooling system 30 includes a water manifold 42 positioned adjacent a top portion 44 of the evaporative cooling pad 40. In one form, water enters the top portion 44 of the evaporative cooling pad 40 and will flow generally downward due to gravitational force to a bottom portion 46. In some forms, a continuous flow of water can be supplied to the evaporative cooling pad 40 and in other forms, the flow of water into the top portion 44 of the evaporative cooling pad 40 may be intermittent. For example, one or more temperature and/or pressure sensors may be used to determine when the evaporative cooling pad 40 has discharged a sufficient amount of water to effectively reduce the desired evaporative cooling effect on the ambient air passing through the evaporative cooling pad 40. A controller in electrical communication with the one or more sensors can be configured to determine a water flow rate required for peak operating cooling efficiency. The source of water may include municipal water supply, ground pumped water supply, and/or condensate collected from a condenser or aftercooler in one or more heat exchanger systems.

The evaporative cooling pad 40 can include a discharge plenum 48 configured to receive the water discharged from the bottom portion 46 of the evaporative cooling pad 40 and direct the drain water into a water tank 50 for storage and re-use. In disclosed embodiment, the discharge plenum 48 can include an inlet 47 and opposing sidewalls 49 that converge to form an outlet 51 that has a smaller flow area than the inlet 47. In other forms the flow area of the outlet 51 may not be smaller than the flow area of the inlet 47. Also it should be understood that the water tank 50 may not be a separate tank, but may be a water collection tank 51 (see FIG. 1) located proximate the bottom portion 46 of the evaporative cooling pad 40.

A pump 52 can be operably connected to the water tank 50. A transfer conduit 54 can be connected between the water tank 50 and the pump 52 so as to provide means for drawing water from the tank 50 to recycle back to the evaporative cooling pad 40 in some embodiments. In some forms, the pump 52 can be located within the water tank 50, however in other forms the pump 52 may be located away from the water tank 50. The pump 52 can pump the water from the tank 50 through an inlet supply conduit 56 that is connected to the water manifold 42. The supply conduit 56 is connected between the pump 52 at one end 57 and an inlet connector 58 extending from the water manifold 42 at a distal end 59. In some forms, the pump 50 may be connected directly to a water tank 51 located at the bottom of the evaporative cooling pad 40.

The water manifold 42 can be of any form known to one skilled in the art. In the disclosed embodiment, the water manifold includes an elongate conduit 60 with multiple outlet holes 61 operable to discharge water to a water distributor 64 along a width of the evaporative cooling pad 40. The water distributor 64 can be designed in many different forms, but in the exemplary embodiment, the water distributor 64 is of a wire mesh construction configured to disperse the water relatively evenly across the top 44 of the evaporative cooling pad 40. In this manner, a relatively even flow of water is distributed across the top 44 and will drain to the bottom 46 across the evaporative cooling pad 40.

An air plenum 70 can be disposed aft or downstream of the evaporative cooling pad 40. The air plenum 70 is configured to receive inlet ambient air flow 12 after the inlet air has passed through the evaporative cooling pad 40. The plenum 70 directs the humidified ambient air into the heat exchanger 14 so as to cool heated fluids discharged from a compressor. Such fluids can include compressed air, discharged oil, or other fluids known to those skilled in the art. A cover 72 can be operatively disposed over portions of the water manifold 42 to prevent ingress of foreign objects such as dirt or the like.

Referring more particularly to FIG. 2, an exemplary blower or fan 80 is operable for providing means for drawing in the ambient cooling air 12 through the evaporative cooling pad 40 and into the heat exchanger 14 to cool heated fluid discharged from the compressor system 10. It should be understood that the blower 80 may blow air directly onto certain components in the heat exchanger system or alternatively draw air in from an inlet positioned away from the blower 80. An exemplary compressor 90 as illustrated can include peripheral components such as an air/oil separator tank 92 or other components 94 such as oil and/or water filters and the like. The compressor 90 can be a contact cooled compressor such as a screw compressor, however in other forms the compressor 90 can be a centrifugal compressor, a piston compressor or other types as is known to the skilled artisan.

In some forms the compressor system 10 can include a housing 100 to cover the components of the compressor system 10. A controller 110 can be configured to control operation of the compressor 90, the pump 52, the blower 80 or other apparatus in the system 10. One or more sensors, including pressure and temperature sensor (not shown) can be used to determine the temperatures, pressures and mass flow rates of the supply water and the inlet air 12 flowing through to the evaporative cooling pad 40. In this manner the system 10 can operate efficiently by preventing undersaturation or oversaturation of the ambient air entering the heat exchanger 14 to provide a desired amount of cooling of fluids in the heat exchanger 14.

The cooling system 30 can be used to cool any number of compressor types and fluids associated therewith. By way of example, and not limitation, various cooling apparatus configurations are illustrated in FIGS. 4A through FIG. 4F. FIG. 4A illustrates a configuration where ambient air flow 12 is directed through an aftercooler prior to passing through an evaporative cooling pad. The air flow 12 passes through an oil cooler heat exchanger downstream of the evaporative cooling pad 40. FIG. 4B illustrates a configuration where cooling air flow 12 passes through an evaporative cooling pad and then is directed to an aftercooler and an oil cooler in series. FIG. 4C illustrates a configuration wherein cooling air flow 12 enters the evaporative cooling pad and then flows to an oil cooler and an aftercooler in parallel. In this form the after cooler and oil cooler each receive cooling air 12 at substantially the same temperature.

In some forms, the cooling system configurations of FIG. 4D-4E can be used in oil free air compressor systems. FIG. 4D illustrates a configuration where the cooling air flow 12 enters an aftercooler and is then directed to an evaporative cooling pad prior to flowing through an inter-stage intercooler. FIG. 4E illustrates a configuration wherein cooling air flow 12 is directed through an evaporative cooling pad and then to an aftercooler prior to flowing to an intercooler. FIG. 4F illustrates a configuration wherein cooling air flow 12 is directed through an evaporative cooling pad and then to an aftercooler and an intercooler in parallel so that each effectively receive cooling air flow at the same temperature.

In one aspect, the present disclosure includes heat exchanger system comprising: an air cooled heat exchanger; an evaporative cooling pad positioned upstream of the air cooled heat exchanger; a water manifold positioned proximate a top side of the evaporative cooling pad; a water tank positioned proximate a bottom side of the evaporative cooling pad; and wherein the water manifold is operable for supplying water to the evaporative cooling pad at the top side and the water tank is operable for receiving water discharged from the evaporative cooling pad at the bottom side thereof.

In refining aspects, the present disclosure includes a pump operable for pumping water from the water tank to the water manifold; a transfer conduit in fluid communication between the tank and the pump; a water supply conduit in fluid communication between the pump and the water manifold; wherein the water manifold includes a plurality of outlet holes projected across the top side of the evaporative cooling pad; comprising a water distributer positioned between the water manifold and the evaporative cooling pad; wherein the water distributor includes a mesh material layer to disperse the water across a width of the top of the evaporative cooling pad; wherein the water includes a mixture of one or more liquids; wherein a compressor is in fluid communication with the air cooled heat exchanger; and wherein compressed fluid and/or oil discharged from the air compressor is cooled in the heat exchanger with the humidified ambient air.

In another aspect, the present disclosure includes a fluid compressor operable for compressing a working fluid; an air cooled heat exchanger operable for cooling the working fluid and/or a lubricant discharged from the compressor; an evaporative cooling pad positioned upstream of the heat exchanger operable for humidifying ambient air prior to entering the heat exchanger; and a water supply apparatus configured to provide water to the evaporative cooling pad.

In refining aspects, the water supply apparatus includes a water manifold positioned proximate a top wall of the evaporative cooling pad, the water manifold having a plurality of outlet ports for discharging a plurality of water streams along a width thereof; wherein the water supply apparatus includes a water distributer positioned between the water manifold and the evaporative cooling pad to disperse the plurality of water streams across a width of the evaporative cooling pad; comprising a discharge manifold positioned adjacent a bottom wall of the evaporative cooling pad, the discharge manifold operable for collecting water flowing from the evaporative cooling pad and discharging the water into a water holding tank; a pump in fluid communication with the tank and the water manifold, the pump operable for pumping water from the tank to the water distributer; a second heat exchanger configured to receive ambient cooling air; wherein the second heat exchanger is positioned upstream of the evaporative cooling pad, in parallel with the heat exchanger or downstream of the heat exchanger; and wherein the heat exchanger and the second heat exchanger is one of an aftercooler, an intercooler, or an oil cooler.

In another aspect, the present disclosure includes a method comprising flowing compressed air discharged from an air compressor to an air cooled heat exchanger; humidifying ambient air upstream of the air cooled heat exchanger, wherein the humidifying includes cooling the ambient air by passing the ambient through an evaporative cooling pad; and exchanging heat between the compressed air and the cooled humidified ambient air within the air cooled heat exchanger.

In refining aspects, the present disclosure includes a method comprising supplying water to the evaporative cooling pad; wherein the supplying includes recycling water from a water tank operable to receive non-evaporated water discharged from the evaporative cooling pad; wherein the water includes a mixture of one or more additional liquid compositions; wherein the humidifying further includes entraining excess water with a flow of the cooled ambient air and evaporating the excess water within the air cooled heat exchanger.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the inventions are desired to be protected. It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow. In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary.

Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 

What is claimed is:
 1. A heat exchanger system comprising: an air cooled heat exchanger; an evaporative cooling pad positioned upstream of the air cooled heat exchanger; a water manifold positioned proximate a top side of the evaporative cooling pad; a water tank positioned proximate a bottom side of the evaporative cooling pad; wherein the water manifold is operable for supplying water to the evaporative cooling pad at the top side and the water tank is operable for receiving water discharged from the evaporative cooling pad at the bottom side thereof.
 2. The heat exchanger of claim 1 further comprising a pump operable for pumping water from the water tank to the water manifold.
 3. The heat exchanger of claim 2 further comprising a transfer conduit in fluid communication between the tank and the pump.
 4. The heat exchanger of claim 2 further comprising a water supply conduit in fluid communication between the pump and the water manifold.
 5. The heat exchanger of claim 1, wherein the water manifold includes a plurality of outlet holes projected across the top side of the evaporative cooling pad.
 6. The heat exchanger of claim 1 further comprising a water distributer positioned between the water manifold and the evaporative cooling pad.
 7. The heat exchanger of claim 6, wherein the water distributor includes a mesh material layer to disperse the water across a width of the top of the evaporative cooling pad.
 8. The heat exchanger of claim 1, wherein the water includes a mixture of one or more liquids.
 9. The heat exchanger of claim 1, wherein a compressor is in fluid communication with the air cooled heat exchanger.
 10. The heat exchanger of claim 1, wherein compressed fluid and/or oil discharged from the air compressor is cooled in the heat exchanger with the cooled humidified ambient air and through evaporation of excess water carried by the humidified ambient air.
 11. A compressor system comprising: a fluid compressor operable for compressing a working fluid; an air cooled heat exchanger operable for cooling the working fluid and/or a lubricant discharged from the compressor; an evaporative cooling pad positioned upstream of the heat exchanger operable for humidifying ambient air prior to entering the heat exchanger; and a water supply apparatus configured to provide water to the evaporative cooling pad.
 12. The system of claim 11, wherein the water supply apparatus includes a water manifold positioned proximate a top wall of the evaporative cooling pad, the water manifold having a plurality of outlet ports for discharging a plurality of water streams along a width thereof.
 13. The system of claim 12, wherein the water supply apparatus includes a water distributer positioned between the water manifold and the evaporative cooling pad to disperse the plurality of water streams across a width of the evaporative cooling pad.
 14. The system of claim 11 further comprising a discharge manifold positioned adjacent a bottom wall of the evaporative cooling pad, the discharge manifold operable for collecting water flowing from the evaporative cooling pad and discharging the water into a water holding tank.
 15. The system of claim 11 further comprising a pump in fluid communication with the tank and the water manifold, the pump operable for pumping water from the tank to the water distributer.
 16. The system of claim 11, further comprising a second heat exchanger configured to receive ambient cooling air.
 17. The system of claim 16, wherein the second heat exchanger is positioned upstream of the evaporative cooling pad, in parallel with the heat exchanger or downstream of the heat exchanger.
 18. The system of claim 16, wherein the heat exchanger and the second heat exchanger is one of an aftercooler, an intercooler, or an oil cooler.
 19. The system of claim 18, wherein the water supply apparatus is configured to supply water condensate discharged from the aftercooler.
 20. A method comprising: flowing compressed air discharged from an air compressor to an air cooled heat exchanger; humidifying ambient air upstream of the air cooled heat exchanger, wherein the humidifying includes cooling the ambient air by passing the ambient through an evaporative cooling pad; and exchanging heat between the compressed air and the cooled humidified ambient air within the air cooled heat exchanger.
 21. The method of claim 20, further comprising supplying water to the evaporative cooling pad.
 22. The method of claim 21, wherein the supplying includes recycling water from a water tank operable to receive non-evaporated water discharged from the evaporative cooling pad.
 23. The system of claim 21, wherein the supplying includes recycling condensate water discharged from an aftercooler and supplying the condensate water to the evaporative cooling pad.
 24. The method of claim 20, wherein the water includes a mixture of one or more additional liquid compositions.
 25. The method of claim 20, wherein the humidifying further includes entraining excess water with a flow of the cooled ambient air and evaporating the excess water within the air cooled heat exchanger. 